Method of electroplating and compositions for use therein



Patented Jan. 17, W

PATENT OFFICE rmnmcx comm, on NEW YORK, N. Y.

METHOD ELEGI'BOPLATING AND COMPOSITIONS FOR USE THEREIN 11o Drawing.

This invention relates to methods of electroplating and ofeleotro-oleaning and to compositions for use therein.

In my Patent No. 1,545,942,

14, 1925, I have described and claimed a brush for use inelectroplating. In my work making use of a brush in the electroplatingand electro-cleaning of metals, I have discovered that improved resultscan be obtained in using the electrolyte in the form of a viscouscomposition, which is referably composed of a colloidal or emulsoidsolution carrying the plating compound, to be electrolyzed. Under theterm plating compound I include any compound or mixture usable fordeposition, with such addition agents, catalysts, or the like as may beusual or desired.

My composition is preferably prepared for commerce in a stiff condition,and 1s preferably made up so as to be non-caking and easily soluble inwater.

In making up my composition, the plating compound is mixed with aviscous watersoluble or miscible constituent, or constitucuts, of whichthere are a large variety suitable for the purpose. The plating compoundis preferably added to the viscous carrier in concentrated form, and, inthe form prepared for commerce, the viscous constituent is sufiicientlythick to give-a composition of approximately the consistency of ordinaryplastic shoe-blacking. The viscous constituent may be varied to suit thenature of the plating compound added thereto. For electrolytic cleaning,my composition is made up in a manner similar to that for plating,except for the substitution of a compound suitable 40 for cleaning. Y

My composition is accordingly compact in volume, easy to ack. does notleak, and in using the same, t ere is a freedom from spatterin orspilling, which results in less loss 45 and inconvenience from drippingand less Application filed larch 28,

granted July 1928. Serial No. 264,270.

mess as compared with the use of the ordinary fluid solutions.

Furthermore, the viscous ingredients combined with the rubbing actionimprove the smoothness and brilliance of the plating. 59

My present invention, as the result of said discoveries, provides animproved process of electroplating whereby greater uniform ity ofplating conditions, and consequently more uniform and perfect deposits,may be obtained by the use of an applying implement and my presentplating compositions than by using ordinaryplating baths or solutions.The invention urther providesaprocess whereby electroplating may becarried out 60 more readily, and with greater neatness and facility thanheretofore carried out with plating baths or solutions.

The invention further provides an improved process of electro-cleaningwhereby the cleaning of surfaces may be efiected more Eapidly,thoroughly and neatly than heretoore.

The invention further provides a novel composition for electroplatingand electrocleaning.

According to my present invention, I or suspend the plating compoundwith a suitable viscous constituent or constituents, and take some of itup in or on the applyin im- 7 plement carrying a suitable electrode.fprefer to use as the applying implement, a brush, dauber or the like,containing a suitable electrode, and work the composition into the brushup to and around the anode contained therein, prior to applying thebrush, dauber orthe like to the object to be plated.

The surface to be plated is first carefully prepared, as by cleaning andsuch other preparatory processes as may be necessary or desired, andthen the plating is effected by wiping or rubbing the surface to beplated with the applying implement carryin the composition. Theelectrode of the a p ying implement is connected in circuit be ore useand the object to be plated is also either connected in the circuit, orto a ground circuit if not already grounded, usually as cathode.

Potential differences and current densities greater than in ordinarybath plating may be and preferably are used, good uniform adhesive platebeing obtained. The action of the plating implement, coupled with theassociation of the plating compound with the viscous carrier, preventstreeing and makes possible deposits of unusually ood appearance andproperties. The time Ior plating is also reduced.

I may and preferably do use current densities at which considerablehydrogen is liberated at the cathode, and I find that by myprocessadherent deposits, even of nickel, can be obtained which are adherent,non-peeling and bright. The quality of the plating deposits isexcellent, as plated sheets may be bent sharply enough to stretch themetal beneath the plate without detaching the plated deposit, and on ahighly polished surface the deposit is sobright as to require nosubsequent polishing.

I also find that with my plating composition the lading of the air withobjectionable vapors such as are given oil by liquid plating baths isimperceptible, as the bubbles formed by the gases resulting from thedissociation of the-electrolyte are held by the solution while underaction on the surface being plated, forming a soapy residue on thesurface being plated or cleaned.

It is convenient to use an already prepared composition in carrying onelectro-platin according to the present invention, though theingredients may be'mixed in or on the applying implement, or otherwise,at the time of use. It is also convenient to manufacture and distributemy new composition in the form of a firm or stiff composition, about ofthe consistency of ordinary plastic shoe blacking. This does not leakand is readily packed and shipped in slip cover containers. This alsoprovides for the retention of a homogeneous distribution of-theingredients in the mixture, after mixing and standing, and is also aconvenient form for use with an applying implement. Moreover, the resultis assured that there is always a uniformity of the electrolyte, as theapplying implement receives a full supply of a uniform electrolyte eachtime that it is replenished from the container, and there does notresult a depletion, as occurs in a bath where the ingredients consumedin plating result in a depletion of the metallic content of the bath. Inthe use of my composition in its preferred form, the brush or the likeis first dipped in Water and afterward rubbed over the surface of thecomposition of stiff consistency, the water dissolving or diluting thecomposition and the bristles'working the eomposition to a creamy orpaint-like consistency,

which can be used without dripping, and enables the electroplating to becarried out overhead, and otherwise, with substantiall the same facilityand neatness as the application of a coat of paint to a surface with apaint brush.

In the case of prepared compositions, it is desirable to prevent ithardenin on standing. In many cases it will beesirable to add anon-drying or moderately hygroscopic substance, to prevent hardening,and for this purpose I may use any suitable substance. I prefer to use asugar or sugar solution or honey, and more particularly cane-sugar orother syrup.

I may also make use of jellies, such as obtained from fruits, andcontaining sugars, and obtain at once a sugar-containing colloid as theviscous constituent.

The viscous constituent is preferably a colloid or emulsoid havingadhesive properties. (lelatines of animal or vegetable origin,'such asobtained from animal tissues, hides, etc. and from sea-weed such asIrish moss, are examples.

In forming my composition, using gelatine as the colloid, I dissolve thegelatine in about double its veight of water and add an amount of thehygroscopic substance which will prevent hardening on shelf-standing.The amount of hygroscopic substance is variable, depending on thesubstance and the amount of water already contained therein. In the caseof cane syrup added to gelatine solution, I preferably use an amountequal to or somewhat more than is equal to the weight of the gelatinesolution.

To this mixture I then add the desired plating compound (convenientlyone of the prepared mixtures sold by chemical and electroplating supplyhouses, and containing such addition agents, catalysts or the like asmay be usual or desired in such mixtures) until the composition stiilensup to the desired consistency, the preferred consistency,

, as stated above, being firm or stiff, about that of ordinary plasticshoe blacking.

A particular example of composition is as follows:

Gelatine 2 ounces (weight) Cane syrup 9 ounces (weight) ater 4 ounces(Weight) Prepared nickel salts Enough to give a stiff consistency.

A mode of procedure in carrying out electroplating with saidcomposition, is to dip a brush, dauber or other ap lying implement (suchfor example as that shown in my Patent No. 1,545,942) into. water andthen into the stiff composition. The applying implement is worked aroundover the surface of the composition, taking up enough of the compositionto form a somecons constituent what thin viscous solution therein orthereon. The brush (connected with the current) is then daubed, rubbedor wiped over a prepared metallic surface. The ainting'action issystematically followed an repeated over a given surface under platingconditions. Any suitable potential difference and current density may beem loyed. For examample, the potential di erence between the electrodesmay be 18 volts, and with 1 square inch surface contact between thebrush and cathode surface a current density of approximately 3 ampcresper square inch is obtained, using the above composition.

In carrying out electrolytic cleaning, 1 preferably use an acid or asalt solution (as for example acetic acid or an ammonium salt) with theapplying implement, for example a brush, and preferably use this acid orsalt in admiiiture with a viscous constituent, preferably a colloidalsolution, such for example as a gelatine solution, and preferably alsowith an ingredient to prevent hardening on standing, the compositionbeing preferabl made up as heretofore described, substituting the aceticacid or other appropriate compound for the plating compound. Thecomposition is preferably taken up at a creamy consistency, either byhaving the composition at such consistency or reducing it to suchconsistency with water.

The applying implement is connected in circuit and wiped or rubbed overthe surface to be cleaned, the current releasing hydrogen on the metalsurface, and the combined action of hydrogen bubbles and mechanicalaction of the applying implement, efi'ect cleaning much more rapidly andthoroughly than is carried out in a bath. Either direct or alternatingcurrent may be used in the cleaning process or method.

Moreover, I may also add a compound having a chemical cleaning action,asfor example, an ammonium salt, and thereby obtain a combinedmechanical, electro-chemical and chemical cleaning action.

By-using a composition comprising a visas the carrier of the acid (orother compound) cleaning may be readily carried outneatly on articles insit-u. dropping or corrosive liquid being avoided by exercisingreasonable care. Dispersion of corrosive vapors to the atmosphere isalso much diminished. I

Various other forms of the composition than the specific composition setforth herein may be used, without departing from the idea of invention,and the process may also be practiced in other forms than that hereinspecifically set forth.

What is claimed is 1. A method of electroplating with a brush havingfree bristles between or among which the electrolytic solution iscarried,

and an electrode among the bristles, compris-. A

in impregnating the spaces between thebristles with a. solutioncontainin a dis solved compound of the metal to be eposited and asubstance for increasing the viscosity" of the solution to counteractthe flow of the solution away from the bristles and the electrodetherein under pressure applied to the brush in its application, andpassing current from the electrode in said brush to a conducting surfaceto which the solutionladen brush is applied.

' 2. Amethod of electroplating with a brush having free bristles betweenor among which the electrolytic solution is carried, and an electrodeamong the bristles, comprising impregnating the spaces between thebristles with a solution containng a dissolved compound of the metal tobe deposited and a col,- loidal substance for increasing the viscosityof the solution to counteract the flow of the solution away from the.bristles and the electrode therein under pressure applied to the brushin its application, and passing current from the electrode in said brushto a conducting surface to which the solution- I,

laden brush is applied.

3. A composition for use with a brush in electro-deposition under theaction of an electro-motive-force imposed from a source outside of awater solution of a metal compound constituent of thecomposition,'and'the constituents of which composition areelectro-chemically inactive among themselves in water solution,containing a water soluble compound of a metal to be deposited, and acolloid. Y

4. A composition for use with a brush in electro-deposition under theaction of an electro-motive-force imposed from a source outside of awater solution of a metal compound constituent of the composition, andthe constituents of" which composition are electro-chemically inactiveamong themselves in water solution, containing a water soluble compoundof a metal to be deposited, and a colloid, and sufiicient water to formwith said constituents a stiff paste, the constituents being thoroughlyintermixed, whereby a uniform distribution of the constituents isobtained in the composition and maintained during handling of thecomposition during long standing of the composition prior to use, saidpaste requiring dilution with water for use.

5. A composition for use with a brush in electro-deposition under theaction of an eleetro-motive-force imposed from a source outside of awater solution of a metal compound constituent of the composition, andthe constituents of which composition are electro-chemically inactiveamong themselves in water solution, comprising a water soluble compoundof a metal to be deposited, a colloid, and a hygroscopic substance, and

sufiicient water to form with said constituents a stifi paste, theconstituents being thorou tr fihly intermixed, whereby a uniform disiution of the constituents is obtained in 5 the comfosition andmaintained during handling 0 the comnosition during long standing of thecomposition prior to use, said paste requiring dilution with water ferIn witness whereof, I have hereunto signed my name.

FREDERICK CONLIN.

